Risk analysis is a diverse subject that derives its breadth from the need to design and manufacture everything from small individual parts and devices to large systems. The role of a mechanical engineer is to take a product from idea to market. To do this, a wide range of skills are needed. the mechanical engineer must acquire special skills and knowledge. He/she must understand the forces and thermal environment that a product, its parts or subsystems will encounter; to design them for functionality, aesthetics and ability to withstand the stresses and thermal environment to which they will be subjected; and to determine the best way to manufacture them and ensure that they will work without failure. Perhaps the one skill that is the exclusive domain of the mechanical engineer is the ability to analyze and design objects and systems with motion.